From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 587D0ECAAD8 for ; Wed, 21 Sep 2022 16:52:28 +0000 (UTC) Received: from localhost ([::1]:43882 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ob2xX-0005kK-BA for qemu-devel@archiver.kernel.org; Wed, 21 Sep 2022 12:52:27 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:52446) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ob2w0-00051t-SJ for qemu-devel@nongnu.org; Wed, 21 Sep 2022 12:50:52 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:60409) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ob2vx-0007sW-Uk for qemu-devel@nongnu.org; Wed, 21 Sep 2022 12:50:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1663779048; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rGUg9eaE4Xn3faFg7EwSOSMv/gvNBmjodT9pDnGRrrE=; b=W5Dw2pRp9QN1HcOJcm6ypelJNsvrfwS2tT5WEl2PIXCqJzFnagEp90WtVhgdNDN/nutA71 pg0ABpA6xfDQScDCuESNNMvpM98h9/mqhtJVrY3Gi3W90f45DHYMiymGJ2ux3mk+Z27Yd/ dM2sMCH8IvRCsUtU9669IkCS74KGc9Y= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-653-LusvOuPaNq6ku4y4AZP3qw-1; Wed, 21 Sep 2022 12:50:45 -0400 X-MC-Unique: LusvOuPaNq6ku4y4AZP3qw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 1246A857FAB; Wed, 21 Sep 2022 16:50:45 +0000 (UTC) Received: from redhat.com (unknown [10.33.36.62]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1ECAA40C6EC2; Wed, 21 Sep 2022 16:50:42 +0000 (UTC) Date: Wed, 21 Sep 2022 17:50:40 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: "Dr. David Alan Gilbert" Cc: Bin Meng , qemu-devel@nongnu.org, Xuzhou Cheng , Bin Meng , =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , Juan Quintela , Laurent Vivier , Paolo Bonzini , Thomas Huth Subject: Re: [PATCH v2 26/39] tests/qtest: migration-test: Make sure QEMU process "to" exited after migration is canceled Message-ID: References: <20220920103159.1865256-1-bmeng.cn@gmail.com> <20220920103159.1865256-27-bmeng.cn@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/2.2.6 (2022-06-05) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, Sep 21, 2022 at 05:29:55PM +0100, Dr. David Alan Gilbert wrote: > * Bin Meng (bmeng.cn@gmail.com) wrote: > > From: Xuzhou Cheng > > > > Make sure QEMU process "to" exited before launching another target > > for migration in the test_multifd_tcp_cancel case. > > > > Signed-off-by: Xuzhou Cheng > > Signed-off-by: Bin Meng > > Reviewed-by: Marc-André Lureau > > Hmm you might want to put a small usleep in that loop; otherwise > it'll burn CPU. > > There is a slim risk with this that another, entirely unrelated, process > will start up with the same PID between the end of migrate_cancel > and then you'll be spinning on it rather than the 'to' qemu. > > I wonder if there's a better way to check for it dieing; e.g. an error > on it's qmp interface or something? Both the qtest and qmp sockets should give EOF. So if there's an API that can call g_poll() on the FD with POLL_HUP event, it would be the reliable way to detect it, without busy-looping. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|